Pillar Guide · Updated July 2026
UK Equal Pay Claims: A Practical Guide for 2026/27
Equal pay is frequently confused with the gender pay gap, but the two are legally distinct: equal pay is an individual, enforceable contractual right under the Equality Act 2010 to the same pay as a comparator of the opposite sex doing equal work. This pillar guide explains how the sex equality clause operates automatically in every contract, how to identify a valid comparator, the three legal routes to establishing equal work, the material factor defence employers rely on, how far back pay can be recovered, and the practical steps — from grievance to ACAS conciliation to employment tribunal — involved in bringing a claim.
Legal Basis
The Equality Act 2010 implies a “sex equality clause” into every employment contract in Great Britain. This clause automatically modifies any contractual term that is less favourable than the equivalent term enjoyed by a comparator of the opposite sex doing equal work for the same employer, unless the employer can show the difference is genuinely due to a material factor unrelated to sex.
Crucially, an equal pay claim does not require proving the employer intended to discriminate — only that the pay (or other contractual term) difference exists for equal work and cannot be objectively justified. This makes equal pay a distinctive, contract-based right rather than a conventional discrimination claim, although the two often overlap in practice.
Choosing a Comparator
A valid comparator must be a real person of the opposite sex, employed by the same employer (or an associated employer) at the same time, or in limited circumstances a predecessor or successor in the role. Hypothetical comparators are not permitted for an equal pay claim brought under the equal pay provisions specifically — though a hypothetical comparator remains available if the claim is instead framed as general sex discrimination.
Selecting the strongest available comparator, whose role most clearly satisfies one of the three equal work tests, is often the single most important strategic step in building a claim, and is frequently where specialist employment law advice adds the most value.
What Counts as Equal Work
Work is treated as equal under the Equality Act in one of three ways:
- Like work — the same or broadly similar work, where any differences are of only minor practical importance.
- Work rated as equivalent — roles formally evaluated as equal under an analytical job evaluation study.
- Work of equal value — different work that is nonetheless equal once effort, skill and decision-making demands are properly assessed, even without a formal evaluation scheme.
Most contested claims fall into the equal value category, which is typically the most complex to litigate because it often requires an independent expert assessment if the case proceeds to a full tribunal hearing.
The Material Factor Defence
An employer can defeat an equal pay claim by proving the pay difference reflects a genuine material factor unrelated to sex — for example, a location weighting, a market-rate premium genuinely needed to recruit or retain a scarce skill, length of service (subject to limits), or a protected (“red-circled”) salary following a job re-grading.
If the material factor is found to indirectly disadvantage one sex more than the other, the employer must go further and show the factor is objectively justified as a proportionate means of achieving a legitimate business aim. A vague or unevidenced explanation, or one traceable to historically gender-influenced pay-setting practices, will not succeed as a defence.
Gender Pay Gap vs Equal Pay
Gender pay gap reporting, mandatory for employers with 250 or more employees, measures the average pay difference between all men and all women across an entire organisation, and can arise entirely lawfully simply because more men hold senior, higher-paid roles. Equal pay, in contrast, is an individual legal right to the same pay for equal work between a specific comparator pair. An organisation can post a large gender pay gap with no individual equal pay breach at all, and a small gender pay gap does not guarantee the absence of equal pay issues within specific role comparisons — the two measures answer different questions.
Back Pay and Time Limits
A successful equal pay claim can typically recover arrears for up to six years before the claim is issued in England and Wales (a similarly structured but distinctly calculated period applies in Scotland), reflecting the standard contract claim limitation period. Claims connected to the end of employment generally must be brought within six months of leaving, though tribunals retain limited discretion to extend time in specific circumstances — always confirm the current deadline rather than assuming historic figures still apply.
How to Bring a Claim
Most claims start with an internal grievance to the employer, both to seek early resolution and to gather the employer’s explanation for any pay difference. Before lodging an Employment Tribunal claim, ACAS Early Conciliation is a mandatory step (subject to limited exemptions) — you notify ACAS, which offers a period of conciliation with the employer, after which a certificate is issued allowing the tribunal claim to proceed if the matter remains unresolved.
Given the complexity of comparator selection, the equal work tests, and the material factor defence, specialist employment law advice (from a solicitor, trade union, or organisations such as the Equality Advisory and Support Service) is strongly recommended before pursuing a formal claim.
What You Can Recover
A successful claim results in the sex equality clause modifying the claimant’s contractual terms to match the comparator going forward, plus arrears of pay for the recoverable back-pay period, plus interest on those arrears. Unlike general discrimination claims, a pure equal pay claim under the Equality Act does not typically attract additional injury-to-feelings compensation unless combined with, or reframed as, a wider sex discrimination claim — a common approach where the underlying facts support both legal routes.
Notable UK Cases
Large-scale equal value litigation against major UK supermarkets, comparing predominantly female shop-floor retail staff with predominantly male warehouse/distribution staff, has significantly shaped how equal value claims are litigated at scale, confirming that very different-looking roles can still be equal once effort, skill and responsibility are properly assessed. Earlier local government equal pay litigation, arising from historic bonus schemes that disproportionately benefited male-dominated roles, similarly established key principles on the material factor defence and how job evaluation evidence is tested.